Metric BMI check
Sample input
Height: 170 cm Weight: 70 kg
Sample result
- BMI: 24.2
- Category: Normal
- Healthy weight range: 53.5-72.3 kg
- BMI Prime: 0.97
- Ponderal Index: 14.3
BMI Calculator
Calculate your Body Mass Index using metric or imperial units and see your BMI category, healthy weight range, BMI Prime, and Ponderal Index.
Health & Fitnessavailable
BMI Calculator
Calculate adult BMI from height and weight using metric or imperial units.
Units
Result
Enter height and weight to calculate BMI.
Adult BMI note
This calculator is intended for adults 20 and older. BMI is a general screening measure and does not account for muscle mass, body composition, pregnancy, or individual medical conditions.
About BMI Calculator
Use the BMI Calculator to estimate adult Body Mass Index from height and weight. Enter metric or imperial measurements to see BMI, adult BMI category, healthy weight range for the entered height, BMI Prime, and Ponderal Index.
How to use
- Choose Metric or Imperial units.
- Enter height and weight in the fields shown for that unit system.
- Review the live BMI result, adult category, healthy weight range, BMI Prime, and Ponderal Index.
- Use the BMI scale to see where the result sits across adult BMI ranges.
- Copy the result if you need to save it, or reset the form to start again.
Worked example
Features
- Calculates adult BMI with metric or imperial units.
- Supports height in centimetres or feet and inches.
- Shows adult BMI category using detailed category bands.
- Calculates healthy BMI range and healthy weight range for the entered height.
- Calculates BMI Prime and Ponderal Index.
- Includes a simple visual BMI scale.
- Shows friendly messages for missing, invalid, or zero height and weight values.
- Runs in the browser without requiring an account.
How it works
- Metric BMI is calculated as weight in kilograms divided by height in metres squared.
- Imperial BMI is calculated as 703 multiplied by weight in pounds, divided by height in inches squared.
- The healthy weight range uses BMI 18.5 to 25 for the entered height.
- BMI Prime is calculated by dividing BMI by 25.
- Metric Ponderal Index is calculated as weight in kilograms divided by height in metres cubed.
- Imperial Ponderal Index uses height in inches divided by the cube root of weight in pounds.
- The calculator is intended for adults 20 and older and does not calculate child or teen BMI percentiles.
Common use cases
- Estimating adult BMI from current height and weight.
- Checking the BMI category associated with a height and weight entry.
- Comparing metric and imperial BMI results.
- Finding the healthy weight range for a given height.
- Recording BMI Prime or Ponderal Index alongside BMI.
- Quickly checking BMI values for forms, notes, or personal tracking.
Frequently asked questions
What is BMI?
BMI, or Body Mass Index, is a calculated measure that compares weight with height. It is commonly used as a general adult screening measure.
Who is this BMI Calculator for?
This version is intended for adults 20 and older. It does not calculate child or teen BMI percentiles.
What formula does the metric calculator use?
Metric BMI is calculated as weight in kilograms divided by height in metres squared.
What formula does the imperial calculator use?
Imperial BMI is calculated as 703 multiplied by weight in pounds, divided by height in inches squared.
What BMI categories does the tool show?
The calculator shows Severe Thinness, Moderate Thinness, Mild Thinness, Normal, Overweight, Obese Class I, Obese Class II, and Obese Class III.
How is the healthy weight range calculated?
The healthy weight range uses BMI 18.5 to 25 for the entered height and displays the range in the selected unit system.
What is BMI Prime?
BMI Prime is BMI divided by 25. It compares a BMI value with the upper end of the normal adult BMI range used by this calculator.
What is Ponderal Index?
Ponderal Index is another height-and-weight ratio. This calculator shows it as an extra reference value alongside BMI.
What are the limitations of BMI?
BMI is a general screening tool. It does not account for muscle mass, body composition, pregnancy, or individual medical conditions.
Is this BMI Calculator medical advice?
No. The calculator provides a general estimate only. For personal health questions, speak with a qualified health professional.